I have been doing some research, though I still don't have any
answers.
Looking at the Sun Blade 100, it is a small pci based machine. This
would
be great for my purpose. I should be able put in 2 hard drives,
plus if I
pulled the cdrom, floppy drive and card reader I should be able to
put in
2 more. Does anyone know if the power supply could run this many
drives or
if there is are upgrade options for it? Also, is there a firmware
limit on
the size of a drive that could be put in it?

First - the power supply is a bog standard ATX part if I remember
correctly so if it's too small you can easily upgrade it. Then, if
there is a limit in the firmware that only limits where you can put
the loaders and the kernel, it does not keep NetBSD from accessing
the whole disk.

So, the powersupply shouldn't be an issue. Is the motherboard standard
form factor too? Maybe I could put it into another case.

Have a look, I'd almost bet it's pretty close to ATX.

The Ultra 60 looks like a better system and should easily be able

to hold 4 drives, although it would be more exspensive to colo.
Is there a big

advantagee to having 2 cpus and the larger case? Is there an option
to put the motherboard into a smaller case?

We don't currently support SMP on sparc64 and there's not much room
in the U60 for IDE drives.
It has two dedicated SCA bays, you'd need at least one SCA drive to
boot from since there's no onboard IDE and finding an IDE or SATA
card with fcode ROM could be difficult.

Is there good support for a SATA card (if I wasn't trying to boot
off of
it)? This could be a good solution to possible performance issues
that I

have now.

Any SATA card otherwise supported by NetBSD should work.

The U60 is better in several ways though:
- - it can take 2GB RAM
- - the CPUs can have up to 4MB cache
- - you get four 64bit PCI slots, one 66MHz capable
Downsides:
- - it will suck more power than a Blade 100
- - you need a card to hook up IDE drives ( although you'd probably
want one for the Blade as well, the onboard IDE controller isn't that
fast IIRC )

This is true in either case. I would want to put in a controller that

could handle 500 gb drives. I have read that you had to have 5 volt
cards

for the Sun Blade 100. Do you know if this is true?

Probably. The 66MHz slot in the U60 runs at 3.3v though ( and 32bit /
33MHz cards do work in there as long as they can deal with 3.3v )

Also, I have been using an ATTO SCSI controller and an intel 100+ pro
ethernet card in a mac running NetBSD. Both seem to work incredibly
reliably. Would they work equally as well in a Sun?

Very likely. I don't know what exact kind of ethernet controller the
Blade has on its mainboard but the U60 has a hme, one of the nicest
fast ethernet NICs around.